Expressions Dont Work on Group Nodes

[mrtripie]

Material Maker version:

1.1

OS/device including version:

Windows 10 GTX 1060 6GB

Issue description:

When using an expression on a group node, the node will not update. If the group is buffered it will keep the previous buffered texture (or blank if you re-opened the project), and if not buffered it will just output black.

Steps to reproduce:

1. Add a built-in group node (such as Warp2, Gaussian Blur, Bevel, etc.), or a custom group node.
2. Add a Remote Node
3. Add a Named Parameter the group node
4. Use the Named Parameter in an expression on one of the group node's parameters. (using other expressions such as fract($time) also doesn't work)